The ACT Government should undertake a review of the territory's gas usage, in order to understand whether future infrastructure is necessary, according to Greens MLA Shane Rattenbury.

Mr Rattenbury will today call for a review, to look at what the consequences of the Government's push away from fossil fuels means for gas infrastructure, and customers who choose to continue using gas.

He said he is concerned that gas piping installed in new suburbs will not be used, leaving existing gas users to pick up the tab.

"With new suburbs coming on stream, gas infrastructure is just being installed as a matter of habit," he said.

"[It is] an investment that really needs to be questioned.

"It'll be recouped over many years, and if people are not signing up to it in new suburbs it means that people in existing suburbs with gas connections will be forced to pay for that infrastructure with nobody actually using it."

Mr Rattenbury said rising costs and a move towards renewable energy were deterring Canberrans from using gas.

"The price of gas has been going up quite a lot, and people are starting to find it more economical to use electric sources for heating and the like," he said.

"People do recognise that gas is a fossil fuel and want to go to 100 per cent renewable energy."

Greens to introduce bill to recognise gender diverse parents

In the Legislative Assembly, Mr Rattenbury will also introduce legislation to allow for transgender parents to be recognised on birth certificates.

Under the bill, parents would be given the option of being labelled 'parent one' and 'parent two' on their child's birth certificate, instead of the traditional mother and father.

Mr Rattenbury said the growing prevalence of transgender and gender diverse parenting meant the current law needed to be expanded.

"Parents will now have a greater choice as to how they're referenced on their child's birth certificate," he said.